1. Field
This application relates to ultra-high peak power laser and amplifier systems and methods.
2. Description of Related Art
Certain embodiments relate to apparatus and methods for amplifying optical pulses from compact laser sources through the use of optical parametric amplifying media. Nonlinear optical elements may be employed to provide amplification in a process known as optical parametric amplification (OPA). In such a process, an intense coherent pump beam at a first wavelength interacts with a nonlinear optical element such as a nonlinear optical crystal to produce amplification. One or more output beams at respective second and third optical wavelengths exit the nonlinear optical element. These output beams are referred to as the signal and the idler. In optical parametric amplification, in addition to being pumped, the nonlinear optical element is seeded with radiation at the signal or the idler wavelengths.
The optical parametric amplification process obeys the conservation of energy principle ω1=ω2+ω3, where ω1 is the pump frequency and ω2 and ω3 are the signal and idler frequencies, respectively. The individual values of ω2 and ω3 also satisfy the conservation of momentum condition, which for plane wave interaction is k1=k2+k3 where k1, k2, and k3 are the respective wave vectors for ω1, ω2, and ω3. This latter condition provides for phase-matching. Phase matching can be varied by changing an appropriate phase matching parameter of the nonlinear optical element such as the angle of propagation or the crystal temperature.
If no light is supplied to the nonlinear optical element at ω2 and ω3, the process is referred to as optical parametric generation (OPG). In OPG, seeding is provided by quantum noise.
When ω2=ω3=ω1/2, the process is termed degenerate. When the pump wave ω1 propagates at an angle with respect to the signal wave the amplification process is referred to as noncollinear optical parametric amplification (NOPA).